Cannon Experiment Could Explain Source of Earth’s Water

(CN) – Using high-powered cannons, scientists conducted new studies that could explain how water came to earth via asteroids, according to research published Wednesday.

So far, scientists have not been able to reach consensus on how water arrived on the Earth and other planets in the solar system.

Icy comets hitting the planet’s surface could have caused water to form, but some scientists believe that asteroids containing water were the source.

In a study published Wednesday in the journal Science Advances, scientists from Brown University explained the findings of their experiments, which involved projectiles the size of marbles fired at dry targets made of pumice.

Material similar to chondrites, which are meteorites that came from older asteroids full of water, made up the projectiles.

Earlier models have shown that the water in “impactors” like meteors should boil off at the point of impact, study co-author Pete Schultz explained.

“But nature has a tendency to be more interesting than our models, which is why we need to do experiments,” he said.

Schultz and lead researcher Terik Daly fired the projectiles at speeds of more than 11,000 miles per hour, using the vertical gun range at a NASA research facility.

They copied speeds and angles that have been observed in meteors throughout the solar system. Then after impact, they examined the debris for signs of water trapped inside.

The team found that as much as 30 percent of the water originally found in the impactors was trapped in the debris after the impact.

Most of the water becomes trapped in “impact melt,” which is similar to volcanic rock, and “impact breccias,” which are rocks made up of debris welded together from the impact’s heat.

While the collision destroys parts of the impactor, a vapor plume remains behind that the researchers think could help explain how water is retained.

“The impact melt and breccias are forming inside that plume,” Schultz explained.

“What we’re suggesting is that the water vapor gets ingested into the melts and breccias as they form,” he added. “So even though the impactor loses its water, some of it is recaptured as the melt rapidly quenches.”

Beyond Earth, the findings could help explain ice deposits on Mercury, as well as water found on the moon’s surface.

“[T]his gives us a mechanism for how water can stick around after these asteroid impacts,” Schultz said. “And it shows why experiments are so important because this is something that models have missed.”

 

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